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Path: sserve!manuel.anu.edu.au!munnari.oz.au!uunet!dtix!darwin.sura.net!haven.umd.edu!decuac!pa.dec.com!rdg.dec.com!sixter.var.dec.com!franzoni From: franzoni@sixter.var.dec.com (Mauro Franzoni) Newsgroups: comp.unix.bsd Subject: Re: How do I enable COM3 and COM4? Message-ID: <1992Oct22.111534.17570@rdg.dec.com> Date: 22 Oct 92 11:15:34 GMT References: <veit.719567281@du9ds3> <1992Oct15.014800.729@skitzo.dseg.ti.com> <1992Oct15.162922.24566@fcom.cc.utah.edu> <1992Oct19.032151.29724@cs.cornell.edu> Sender: news@rdg.dec.com (Mr News) Reply-To: franzoni@sixter.var.dec.com (Mauro Franzoni) Organization: Digital Equipment Corporation Lines: 39 > >>In article <1992Oct15.014800.729@skitzo.dseg.ti.com> dittman@skitzo.dseg.ti.com (Eric Dittman) writes: |> >>>How do I enable COM3 and COM4 in the binary distribution of 386BSD 0.1 |> >>>from agate.berkeley.edu? Or do I have to do this from the source? |> >> |> >>You have to modify the configuration file, config, and rebuild the kernel. |> >>Amacio Hasty (I believe) has put together a "minimum required sources" |> >>tar archive on agate and elsewhere for the rebuilding of kernels for those |> >>with only 40Meg of disk. |> >> |> >> |> >You might also want to edit isa.h to add |> >#define IO_COM4 0x2e8 |> >#define IO_COM3 0x3e8 |> |> >and then use in the config file |> >device com2 at isa? port "IO_COM3" tty irq 4 vector comintr |> >device com3 at isa? port "IO_COM4" tty irq 3 vector comintr |> |> >Craig |> |> >p.s. mknod /dev/com2 c 8 2 ; mknod /dev/com3 c 8 3 > This is the obvious "solution", but will cause really dirty problems, provided |> you do not remove the lines for com1 and com2 (or com0/com1, depending how |> they are called). Usually they occupy the irq3 and irq4 lines. So you |> get an interrupt clash for the serial lines, with the effect that data may |> get lost in the situation where two ports on the same irq call for service. |> Don't use the above patch without modifying the com driver irq service |> to take care for these multiple events, even if anyone claims that "this Did anybody write such a modified service routine ? |> works for me". In real situations, it will fail miserably. Yes, it fails - and block all of /dev/com0[1-4] Thanks, M. Franzoni